Re: [PATCH] Implement kasprintf

[Jeremy Fitzhardinge <jeremy@goop.org>]

Randy.Dunlap wrote:
> Doesn't this already add the bloat/code? ::
>   
Yup.  My back-of-the-mind unexamined assumption was that this was going 
into a .a, which it isn't.

Updated patch below.

    J


--

From: Jeremy Fitzhardinge <jeremy@xensource.com>

Implement kasprintf, a kernel version of asprintf.  This allocates the
memory required for the formatted string, including the trailing '\0'.
Returns NULL on allocation failure.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>

---
 include/linux/kernel.h |    2 ++
 lib/vsprintf.c         |   23 +++++++++++++++++++++++
 2 files changed, 25 insertions(+)


diff -r cd45ea4bb813 include/linux/kernel.h
--- a/include/linux/kernel.h	Tue Jun 20 17:28:16 2006 -0700
+++ b/include/linux/kernel.h	Tue Jun 20 17:29:18 2006 -0700
@@ -114,6 +114,8 @@ extern int scnprintf(char * buf, size_t 
 	__attribute__ ((format (printf, 3, 4)));
 extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
 	__attribute__ ((format (printf, 3, 0)));
+extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
+	__attribute__ ((format (printf, 2, 3)));
 
 extern int sscanf(const char *, const char *, ...)
 	__attribute__ ((format (scanf, 2, 3)));
diff -r cd45ea4bb813 lib/vsprintf.c
--- a/lib/vsprintf.c	Tue Jun 20 17:28:16 2006 -0700
+++ b/lib/vsprintf.c	Tue Jun 20 17:29:18 2006 -0700
@@ -849,3 +849,26 @@ int sscanf(const char * buf, const char 
 }
 
 EXPORT_SYMBOL(sscanf);
+
+
+/* Simplified asprintf. */
+char *kasprintf(gfp_t gfp, const char *fmt, ...)
+{
+	va_list ap;
+	unsigned int len;
+	char *p;
+
+	va_start(ap, fmt);
+	len = vsnprintf(NULL, 0, fmt, ap);
+	va_end(ap);
+
+	p = kmalloc(len+1, gfp);
+	if (!p)
+		return NULL;
+	va_start(ap, fmt);
+	vsnprintf(p, len+1, fmt, ap);
+	va_end(ap);
+	return p;
+}
+
+EXPORT_SYMBOL(kasprintf);